This invention relates to a switch device and, more particularly, to a waterproof structure for a switch device.
2. Description of the Prior Art
Various types of switch devices are used depending upon a particular application. In certain applications, a switch device is frequently exposed to moisture, such as rain. One such application may be when the switch device is used in an automobile for controlling the position of an electrically powered seat. It would be desirable to enclose such a switch in a waterproof structure.
A variety of types of waterproof structures have been proposed for various types of switch devices. In a seesaw type switch, such as the type frequently used for controlling and lowering an electrically powered seat within an automobile, the prior art switches typically include a thin rubber sheet, through which a switch actuator for operating the switch is projected, for waterproofing the switch.
In the waterproof structure of the type described above, the rubber sheet is freely elastically deformed when the switch actuator is toggled. Thus, the rubber sheet prevents liquid from entering the upper surface of the switch housing into the interior of the switch. However, since the rubber sheet is made of a soft material, it is difficult to attach the sheet during manufacturing, and, as a result, certain fabrication steps must be performed manually. Additionally, since the elasticity of the rubber itself is limited, when a plurality of switches are mounted in the housing, sufficient waterproofing cannot be expected. Further, if liquid enters the switch housing through the rubber sheet, the liquid may cause an improper electrical contact of the switch.